e2salvage is a utility which tries to do in-place data recovery a from damaged ext2 filesystems. Unlike e2fsck, it does not look for the data at particular places and it don't tend to believe the data it finds; thus it can handle much more damaged filesystem.

e2salvage tries its best to recover the directory structure of the filesystem, if this fails lost files will be linked to root.

e2salvage is still an experimental piece of software - it can do a lot of harm to your filesystem - only run it on a backup of the damaged filesystem to be safe!

06.10.2003 Released slightly updated v. 0.0.8a
30.09.2003 Site moved to sourceforge.net



Linux LVMs with broken disks

Salvaging data on an Linux LVM with all disks working is straight forward: since the filesystem appears as one. However as disk fails it gets more complicated (at least if it is not internally replicated via RAID techniques).

Depending on where the interesting data is stored several options exists. Logical volumes that don't touch the broken disk should be salvagable using vgbackup/restore. For LVs that span the broken disks the answer is slightly more complicated: data on the broken disk will of course be lost, but the remaining disks might contain salvageable data.

To salvage data on volumes that span the broken disk the best shot is the LVM2 partial mode. LVM2 requires the device-mapper which is available either as a patch for Linux kernel 2.4 or included in Linux kernel 2.6. LVM2 is backwards compatible and giving the "--partial" flag to the new tools should enable you to manipulate your LVM even with broken disks. The partial mode relies on a special "ioerror" device which needs to be setup manually Florian Hinzmann has posted a short cookbook on how to do this on the linux-lvm list: here and here (local copies here and here). The device-mapper patch is available from Sistina or as the Debian package "kernel-patch-device-mapper".

After theLVv's are up and running again you should in principle be able to use any recovery tool to restore your data. E2salvage doesn't pay any attention to the broken disks and some files will be garbled (since the data is lost), e2retrieve promises to take special care of broken LVM's.



General e2salvage discussion (compilation problems, usage problems, etc.)


Development related discussion (bug reports, etc.)
At the time of writing e2salvage is at a rather experimental level. It might help you, but it might make a bad situation worse. Use it with care. Here are some of the challenges to be solved: